Objective:: Left ventricular (LV) hypertrophy (LVH) predicts adverse cardiac events in adults. We sought to determine the risk factors and prognostic significance of altered LV geometry in preterm infants. Study design:: In an echocardiographic, single-center, retrospective case-control study we investigated the risk factors and outcomes in patients with altered LV geometry (either increased left ventricular mass index (LVMI) or increased relative wall thickness (RWT)) from a cohort of 503 preterm infants ≤2 kg. Result:: Altered LV geometry was seen in 180 patients and was predicted by postnatal steroids and small for gestational age. Hospital stay was longer in the elevated RWT cases. Altered LV geometry resolved in 129 of the 131 cases with follow-up echocardiogram. Fifteen of 94 patients with elevated RWT died compared to 3/90 controls (P = 0.004). Conclusion:: Altered LV geometry in preterm infants is associated with postnatal steroid use and small for gestational age. Elevated RWT is associated with longer hospital stay and increased mortality.